US2502476A - Producing transparent protective films on zinc or cadmium - Google Patents
Producing transparent protective films on zinc or cadmium Download PDFInfo
- Publication number
- US2502476A US2502476A US30744A US3074448A US2502476A US 2502476 A US2502476 A US 2502476A US 30744 A US30744 A US 30744A US 3074448 A US3074448 A US 3074448A US 2502476 A US2502476 A US 2502476A
- Authority
- US
- United States
- Prior art keywords
- zinc
- cadmium
- transparent protective
- protective films
- producing transparent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 title claims description 14
- 229910052725 zinc Inorganic materials 0.000 title claims description 14
- 239000011701 zinc Substances 0.000 title claims description 14
- 229910052793 cadmium Inorganic materials 0.000 title claims description 11
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 title claims description 11
- 230000001681 protective effect Effects 0.000 title description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 15
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 9
- 229940117975 chromium trioxide Drugs 0.000 claims description 7
- WGLPBDUCMAPZCE-UHFFFAOYSA-N chromium trioxide Inorganic materials O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 7
- GAMDZJFZMJECOS-UHFFFAOYSA-N chromium(6+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Cr+6] GAMDZJFZMJECOS-UHFFFAOYSA-N 0.000 claims description 7
- 230000003647 oxidation Effects 0.000 claims description 7
- 238000007254 oxidation reaction Methods 0.000 claims description 7
- 239000007864 aqueous solution Substances 0.000 claims description 6
- 150000002739 metals Chemical class 0.000 claims description 5
- 239000002932 luster Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 238000000576 coating method Methods 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 238000005266 casting Methods 0.000 description 3
- 230000007935 neutral effect Effects 0.000 description 3
- 229910021653 sulphate ion Inorganic materials 0.000 description 3
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 239000001166 ammonium sulphate Substances 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 238000002845 discoloration Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000001117 sulphuric acid Substances 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 description 1
- 239000011686 zinc sulphate Substances 0.000 description 1
- 235000009529 zinc sulphate Nutrition 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/24—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds
Definitions
- Patented Apr. 4, 1950 UNITED sures PATENT OFFICE PRODUCING TRANSPARENT PROTECTIVE FILMS ON ZINC OR CADMIUM Lawrence H. Ott, Pasadena, Calii'., and James T.
- the zinc surface loses its bright luster and becomes coated with an oxidation product sometimes called white bloom.
- the manufacturer desires to deliver his product to the consumer with a bright metallic surface.
- the zinc coated products are usually stored in the manufacturer's or jobbers warehouse for a considerable period. In the damp atmosphere of the warehouse the coat- Even coated sheets that are stacked in contact become covered with the dull bloom in a short time.
- compositions and a process 4 employing a chemical dip which will overcome Our invention preserves the original bright metallic luster of the metallic products and provides a basis for paint if it is desired to add such a coating to the object.
- compositions are available as concentrates for dilution with water to produce a dip or bath capable of forming a transparent, corrosion resistant, protective film on coatings or castings of zinc and cadmium.
- the metal surfaces treated under the foregoing conditions retain their luster with substantially complete freedom from zinc rust, and, moreover, withstand a salt spray test throughout a commercially feasible time cycle.
- neutral salts such as zinc sulphate, ammonium sulphate or sodium sulphate are added to the formula of Example I in critical amounts to produce a concentration of the sulphate radical (S04) of about to mg./l.
- Example II CrOa 1 gm./l HCI l m1./l ZnSOr'IHzO 0.2 to 0.4 gmL/l
- the pH is maintained within the range indicated for Example I and the other critical treating conditions described are observed.
- the solutions may be used as treating agents by spraying the same upon the obj ects-
- the important results obtained are the maintenance of the luster and freedom from oxidation and without producing discoloration of the articles.
- An aqueous solution for use in the treatment of metals selected from the group consisting of zinc and cadmium to preserve the luster thereof and reduce oxidation consisting essentially of a 1:1 ratio of an equal number of grams of chromium trioxide to an equal number of milliliters of hydrochloric acid (36 to 38%).
- An aqueous concentrated solution for use in the treatment of metals selected from the group consisting of zinc and cadmium to preserve the luster thereof and reduce oxidation consisting essentially of a 1:1 ratio of an equal number of 3 grams of chromium trioxide to an equal number of milliliters of hydrochloric acid (36 to 38%).
- An aqueous solution for use in the treatment of metals selected from the group consisting of zinc and cadmium to preserve the luster thereof and reduce oxidation consisting essentially of 1 gram per liter of chromium trioxide and 1 milliliter'per liter of hydrochloric acid (36 to 38%).
- the process of treating metals selected from the group consisting of zinc and cadmium to preserve the luster thereof and reduce oxidation which comprises treating the metal with an aqueous solution consisting essentially of 1 gram per liter of chromium trioxide and one milliliter per liter of hydrochloric acid (36 to 38%), said solution having a temperature between 70 and 212 F. and the treatment of the metal being conducted for 50 to 120 seconds.
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
Description
' ing soon begins to oxidize.
the defects mentioned above.
Patented Apr. 4, 1950 UNITED sures PATENT OFFICE PRODUCING TRANSPARENT PROTECTIVE FILMS ON ZINC OR CADMIUM Lawrence H. Ott, Pasadena, Calii'., and James T.
Shewbridge,
Baltimore,
Md assignors to Rheem Manufacturing Company, New York, N. Y., a corporation of California No Drawing.
- the zinc surface loses its bright luster and becomes coated with an oxidation product sometimes called white bloom. The manufacturer desires to deliver his product to the consumer with a bright metallic surface. However, in normal distribution practices the zinc coated products are usually stored in the manufacturer's or jobbers warehouse for a considerable period. In the damp atmosphere of the warehouse the coat- Even coated sheets that are stacked in contact become covered with the dull bloom in a short time.
It has been a practice to coat mill galvanized sheets at the factory with oil to overcome the tendency to oxidize. However, this treatment is not completely satisfactory, and furthermore it must be removed before painting can be attempted. Attempts have been made to use chromic acid and mineral acid dips to inhibit corrosion. However, in most cases, the dips have been too expensive or difilcult to apply, or produce a visible colored coating which detracts from the metallic appearance.
We have devised compositions and a process 4 employing a chemical dip which will overcome Our invention preserves the original bright metallic luster of the metallic products and provides a basis for paint if it is desired to add such a coating to the object.
These compositions are available as concentrates for dilution with water to produce a dip or bath capable of forming a transparent, corrosion resistant, protective film on coatings or castings of zinc and cadmium.
We have discovered that improved results are obtained by employing a dilute aqueous solution containing chromium trioxide (CrOa) and hydrochloric acid (36 to 38%) wherein there is about a 1:1 ratio of an equal number of grams of chromium trioxide to'an equal number of milliliters of hydrochloric acid. Other critical conditions surrounding the method of treatment are a solution having a pH between about 1.75 and 2.05, an immersion period of 5 to 120 seconds, with best results at about seconds, a bath temperature between about and 212 F. with the Application June 2, 1948, Serial No. 30,744
6 Claims. (Cl. i466.21)
2 optimum at about 180 F., followed by a final rinse in hot or cold water at a temperature of about 70 to140 F.
Example 1 C103 l gm./l HCl 1 ml./l
The metal surfaces treated under the foregoing conditions retain their luster with substantially complete freedom from zinc rust, and, moreover, withstand a salt spray test throughout a commercially feasible time cycle.
Preferably, neutral salts such as zinc sulphate, ammonium sulphate or sodium sulphate are added to the formula of Example I in critical amounts to produce a concentration of the sulphate radical (S04) of about to mg./l.
Example II CrOa 1 gm./l HCI l m1./l ZnSOr'IHzO 0.2 to 0.4 gmL/l The pH is maintained within the range indicated for Example I and the other critical treating conditions described are observed.
While a preferred method of treating is to immerse the coated metal products or castings in solutions of the character described, the solutions may be used as treating agents by spraying the same upon the obj ects- The important results obtained are the maintenance of the luster and freedom from oxidation and without producing discoloration of the articles.
In referring to zinc and cadmium in the appended claims we intend to include coatings and castings of these materials as well as alloys containing an appreciable amount of the same.
This application is a continuation-in-part of our copending application, Serial No. 754,062, filed June 11, 1947, now abandoned.
We claim:
p 1. An aqueous solution for use in the treatment of metals selected from the group consisting of zinc and cadmium to preserve the luster thereof and reduce oxidation consisting essentially of a 1:1 ratio of an equal number of grams of chromium trioxide to an equal number of milliliters of hydrochloric acid (36 to 38%).
2. An aqueous concentrated solution for use in the treatment of metals selected from the group consisting of zinc and cadmium to preserve the luster thereof and reduce oxidation consisting essentially of a 1:1 ratio of an equal number of 3 grams of chromium trioxide to an equal number of milliliters of hydrochloric acid (36 to 38%).
3. An aqueous solution for use in the treatment of metals selected from the group consisting of zinc and cadmium to preserve the luster thereof and reduce oxidation consisting essentially of 1 gram per liter of chromium trioxide and 1 milliliter'per liter of hydrochloric acid (36 to 38%).
4. An aqueous solution according to claim 3 containing a neutral salt of sulphuric acid in an 10 amount to produce a concentration of the sulphate radical of 75 to 150 mg./l which will not discolor the zinc or cadmium surface.
5. The process of treating metals selected from the group consisting of zinc and cadmium to preserve the luster thereof and reduce oxidation which comprises treating the metal with an aqueous solution consisting essentially of 1 gram per liter of chromium trioxide and one milliliter per liter of hydrochloric acid (36 to 38%), said solution having a temperature between 70 and 212 F. and the treatment of the metal being conducted for 50 to 120 seconds.
6. The process according to claim 5 wherein the solution contains a neutral salt of sulphuric 4 acid in amount to produce a concentration of the sulphate radical of 75 to 150 mg./1 which will not discolor the zinc or cadmium surface.
LAWRENCE H. OTT. JAMES T. SHEWBRIDGE.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS OTHER REFERENCES H. T. S. Britton, "Hydrogen Ions, published 1929. page 48, D. Van Nostrand 00., Inc., New York.
Claims (1)
1. AN AQUEOUS SOLUTION FOR USE IN THE TREATMENT OF METALS SELECTED FROM THE GROUP CONSISTING OF ZINC AND CADMIUM TO PRESERVE THE LUSTER THEREOF AND REDUCE OXIDATION CONSISTING ESSENTIALLY OF A 1:1 RATIO OF AN EQUAL NUMBER OF GRAMS OF CHROMIUM TRIOXIDE TO AN EQUAL NUMBER OF MILLILITERS OF HYDROCHLORIC ACID (36 TO 38%).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US30744A US2502476A (en) | 1948-06-02 | 1948-06-02 | Producing transparent protective films on zinc or cadmium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US30744A US2502476A (en) | 1948-06-02 | 1948-06-02 | Producing transparent protective films on zinc or cadmium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2502476A true US2502476A (en) | 1950-04-04 |
Family
ID=21855790
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US30744A Expired - Lifetime US2502476A (en) | 1948-06-02 | 1948-06-02 | Producing transparent protective films on zinc or cadmium |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2502476A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2709847A (en) * | 1951-05-04 | 1955-06-07 | Bendix Aviat Corp | Cadmium plated aluminum and the method of making the same |
| US2796361A (en) * | 1953-04-15 | 1957-06-18 | Poor & Co | Method of making corrosion protected articles |
| US2799601A (en) * | 1955-04-22 | 1957-07-16 | Allied Res Products Inc | Composition and method for coating zinc and zinc alloy sheets |
| US2861019A (en) * | 1956-06-07 | 1958-11-18 | Dow Chemical Co | Chromate-coating magnesium and its alloys |
| US3039900A (en) * | 1959-04-01 | 1962-06-19 | Cornigliano Societa Per Azioni | Method to form a film for protection against corrosion on sheets of galvanized steel |
| DE1167621B (en) * | 1959-05-14 | 1964-04-09 | Raymond Druckknopf Und Metallw | Solution and process for the production of a smudge-proof, scratch-proof and moisture-proof anti-corrosion coating on zinc and cadmium surfaces |
| US3405014A (en) * | 1964-03-10 | 1968-10-08 | Mitsui Mining & Smelting Co | Process for producing dyed chromate films on zinc and zinc alloys |
| US4776898A (en) * | 1985-03-20 | 1988-10-11 | Omi International Corporation | Passivation |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB275781A (en) * | 1926-07-30 | 1927-08-18 | William Herbert Hatfield | Improvements in or relating to the treatment of the surfaces of stainless or rustless steels or irons |
| US2088429A (en) * | 1936-03-10 | 1937-07-27 | Gen Electric | Bright zinc |
| US2186579A (en) * | 1933-06-28 | 1940-01-09 | Udylite Corp | Method of brightening metals electronegative to iron |
| US2393663A (en) * | 1943-03-22 | 1946-01-29 | Rheem Res Products Inc | Coating for cadmium and zinc |
| US2393665A (en) * | 1944-03-27 | 1946-01-29 | Rheem Res Products Inc | Corrosion resistant metal |
-
1948
- 1948-06-02 US US30744A patent/US2502476A/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB275781A (en) * | 1926-07-30 | 1927-08-18 | William Herbert Hatfield | Improvements in or relating to the treatment of the surfaces of stainless or rustless steels or irons |
| US2186579A (en) * | 1933-06-28 | 1940-01-09 | Udylite Corp | Method of brightening metals electronegative to iron |
| US2088429A (en) * | 1936-03-10 | 1937-07-27 | Gen Electric | Bright zinc |
| US2393663A (en) * | 1943-03-22 | 1946-01-29 | Rheem Res Products Inc | Coating for cadmium and zinc |
| US2393665A (en) * | 1944-03-27 | 1946-01-29 | Rheem Res Products Inc | Corrosion resistant metal |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2709847A (en) * | 1951-05-04 | 1955-06-07 | Bendix Aviat Corp | Cadmium plated aluminum and the method of making the same |
| US2796361A (en) * | 1953-04-15 | 1957-06-18 | Poor & Co | Method of making corrosion protected articles |
| US2799601A (en) * | 1955-04-22 | 1957-07-16 | Allied Res Products Inc | Composition and method for coating zinc and zinc alloy sheets |
| US2861019A (en) * | 1956-06-07 | 1958-11-18 | Dow Chemical Co | Chromate-coating magnesium and its alloys |
| US3039900A (en) * | 1959-04-01 | 1962-06-19 | Cornigliano Societa Per Azioni | Method to form a film for protection against corrosion on sheets of galvanized steel |
| DE1167621B (en) * | 1959-05-14 | 1964-04-09 | Raymond Druckknopf Und Metallw | Solution and process for the production of a smudge-proof, scratch-proof and moisture-proof anti-corrosion coating on zinc and cadmium surfaces |
| US3405014A (en) * | 1964-03-10 | 1968-10-08 | Mitsui Mining & Smelting Co | Process for producing dyed chromate films on zinc and zinc alloys |
| US4776898A (en) * | 1985-03-20 | 1988-10-11 | Omi International Corporation | Passivation |
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